Current heads-up display (HUD) systems require complex display projection/combiner hardware. A typical HUD contains a projector unit, a combiner, and a display computer. The projection unit in a typical HUD is an optical collimator with a convex lens or concave mirror and a display element producing an image where the light is collimated. The combiner is typically an angled flat piece of glass (a beam splitter), located directly in front of the viewer, that redirects the projected image from projector in such a way as to see the field of view and the projected image at the same time. The combiner may have a special coating that reflects the monochromatic light projected onto it from the projector unit while allowing all other wavelengths of light to pass through. In some optical layouts, combiners may also have a curved surface to refocus the image from the projector.
Existing HUD systems are not suitable for installation into many airplanes because of weight and complexity. Consequently, it would be advantageous if an apparatus existed that is suitable for providing HUD functionality in vehicles.